Up to 11mm length. Third submarginal cell almost triangular; comb spines of inferior row on fore basitarsus longer than those of superior row; erect hairs of thorax fine, short, with a few fine hairs on propodeum; largely with dark pubescence.  The commonest of our three black Anoplius species and fairly frequent in a variety of habitats featuring light, sparsely-vegetated soils, especially clays. This includes woodland clearings, arable, brownfield sites, dry grasslands and gardens. A. carbonarius is scarcer, often tied to damp woodlands where it can source the mud necessary for its specialized architecture. 

Unless identified by a recognised expert, a photo is required and the specimen should be examined with a microscope. In the comments box, state the key or ID method used and describe the size and identifying characters.

May to September.

Common and widespread.

Unknown.

BWARS: https://bwars.com/wasp/pompilidae/pompilinae/anoplius-nigerrimus

Spider wasps. Hymenoptera: Pompilidae, vol. 6 Part 4. London: Royal Entomological Society of London, 1988, p. 60. Available at: https://www.royensoc.co.uk/wp-content/uploads/2021/12/Vol06_Part04.pdf